Facebook sought to quell the controversy stemming from accusations of bias creeping into its Trending Topics feature Thursday, publishing an explainer that breaks down the inner workings of the curation feature.

At its core, Trending Topics is designed to help people discover major events and meaningful conversations. Trending Topics is a feature we added in 2014 — separate from a person’s News Feed — to help people discover content that is both popular in the world and meaningful to them.

Topics that are eligible to appear in the product are surfaced by our algorithms, not people. This product also has a team of people who play an important role in making sure that what appears in Trending Topics is high-quality and useful.

The explainer comes in the wake of an anonymously sourced exposé published by Gizmodo in which a former Facebook worker said Facebook's Trending Topics section sometimes excluded conservative sources.

The disclosure resulted in fallout from Facebook users, future-of-media types and even a United States senator, who asked that the social network make its practices for curating the section more transparent.

In its statement, Facebook describes Trending Topics as the result of a three-step process that uses an algorithim to surface newsworthy stories, which are then reviewed by a member of its Trending Topics team and personalized.

Potential Trending Topics are first surfaced by an algorithm that identifies topics that have recently spiked in popularity on Facebook (in other words, ones that have a high volume of mentions and a sharp increase in mentions over a short period of time). The Trending Topics algorithm also uses an external RSS website crawler to identify breaking events so that we can connect people to conversations on Facebook about newsworthy events as quickly as possible.

Facebook's statement echoes a story published earlier today by The Guardian which detailed the inner workings of Trending Topics. The story, which relied on internal guidelines from Facebook, described the feature as being ultimately controlled by human editors rather than algorithms.

Since Gizmodo published its expose, Facebook has launched a public relations effort seeking to reinforce its longtime stance as a neutral arbiter of content published to the social network. In a lengthy Q-and-A with The Verge's Casey Newton Thursday, Facebook News Feed boss Will Cathcart sought to explain how Trending Topics and News Feed work to create "the product that people want" with a mix of algorithmic filtering and human curation.